Submission #481772

#	Time	Username	Problem	Language	Result	Execution time	Memory
481772		blue	버섯 세기 (IOI20_mushrooms)	C++17	79.58 / 100	10 ms	328 KiB

mushrooms

#include "mushrooms.h"
#include <vector>
#include <iostream>
using namespace std;

const int X = 250; //199

int ceil_div(int a, int b)
{
    return a/b + bool(a%b);
}

int count_mushrooms(int n)
{
    if(n <= 227)
    {
      int ans = 1;
      for(int i = 1; i < n; i++) ans += !use_machine(vector<int>{0, i});
      return ans;
    }

    vector<int> typ[2];
    typ[0].push_back(0);

    for(int i = 1; i <= 2; i++)
      	typ[ use_machine(vector<int>{0, i}) ].push_back(i);

    int B = 0;
    if(int(typ[1].size()) >= 2) B = 1;

    int maxV = 0;

    for(int i = 3; i+1 <= min(n-1, X); i += 2)
    {
        int U = use_machine(vector<int>{typ[B][0], i, typ[B][1], i+1});

        if(B == 0)
        {
          	typ[U/2].push_back(i);
            typ[U%2].push_back(i+1);
		}
        else
        {
          typ[!(U/2)].push_back(i);
          typ[!(U%2)].push_back(i+1);
        }

        maxV = i+1;
    }

    vector<int> ans{(int)typ[0].size(), (int)typ[1].size()};

    int base = (int)typ[0].size() > (int)typ[1].size() ? 0 : 1;
    int ct = (int)typ[base].size();

    // cerr << ans[0] << ' ' << ans[1] << '\n';

    for(int v = 1+maxV; v < n; v += ct-1)
    {
        // cerr << "V = " << v << '\n';
        vector<int> query{typ[base][0]};
        for(int i = v; i < v+ct-1 && i < n; i++)
        {
            query.push_back(i);
            query.push_back(typ[base][i-v+1]);
        }

        int Q = use_machine(query);
        int rem = (int)query.size() - 1  -  Q;

        ans[base] += rem/2;
        ans[!base] += Q/2;
    }
    return ans[0];
}

• Subtask 1: 79.5775 / 100